Flotation process



Patented June 19,

UNITED STATES PATENT ()FFICE norA'rroN raocas's y I Edward H. Hoag, Los Angeles, Calif. Application March 3, 1943, Serial No. 471,838

Claim.

it is the object of this invention to improve or combine low cost chemicals into a flotation reagent which has powerful collecting properties forbaryta ores with depressing properties for,

undesirable minerals, such as limestones, sili- The combination of chemicals referred to above, for example, consists of a mixture of talloel (75%), la'uric-acid-ester-diethylene-glycolammonium-sulphate (20%), and octyl alcohol (5%) or thereabouts. Also, it may consist of a combination of'said chemicals in various proportions whereby an emulsion is formed which may be almost or completely soluble in water.

The minute quantities of said reagent that are utilized for collecting and frothing purposes for baryta as well as for depressing limestone, siliceous minerals, iron oxides and the cost of said chemicals gives it advantages over other re agents for like purposes. the extraction of baryta concentrate is better and o! a higher specific gravity and quality.

According to the present invention a new process with improved results are'obtained by the use of the above reagent and method which are set forth for concentratingbaryta ores and sepa rating said 'barite from siliceous minerals, heavy It is more eficient.

from other minerals in a flotation bath. Alone bles for i'rothing purposes.

Lauric acid ester diethylene glycol ammonium-sulphate-when introduced into a flotaare combined for similar. purposes.

The combination 0! the three chemicals functions cooperatively in producing new and better 1 results; anigthey become a complete flotation reagent, that is, a reagent which collects, acts as a i'rother for desirable minerals, and. depresses undesirable minerals. Each member of the group modifies each succeeding member to improve-the final unitary result; that is, it improves the final activation and collection of barite in a selective manner in the form of a high grade concentrate collected in a flotation froth, while at the same time it partly depresses siliceous minerals, limestone, iron and alumina oxides. In this manner it causes an economical separation of barite in the form of a concentrate from the ociated' minerals contained therein.

The solution, an emulsion of the oil-in-water type serves particularly for the hydration of colloidal particles as well as for ion exchange of said particles, especially for cation exchange and .for its property of being soluble in water; and

also, for being more rapidly wetted bywater than by oil.

' It is possible to get very good results by mixing iron and alumina oxides, manganese, titanium,

limestone, alkalie earths, colloidal-iron and alumina hydroxides and impurities, according to the results indicated in Tables Nos. 1, 2, 3 and 4.

These tables give the analysis of the different products obtained such as concentrates, colloids, colloids middlings, middlings and tails,- their assay values per tonof ore, weight percent and'distribution percent for tests made on baryte ore.

tallcel lauric-acid-ester-diethylene-glycol-ammc= mum-sulphate with octanols, or hexanols, or heptanols, or primary alcohols of the general ionmula CnHlin-HOH, chosen from the groups having low solubility and marked surface tension property, for example,'hexanols, heptan'ols,

octanols, nonanols, decanols and d0decanols,or diethylene glycol-mono-ethyl-ether, or Dupcnt In Table No. 1 the midds include colloids and colloids midds.

Talloel when introduced into a flotation bath "lecting properties which are selective for'barite 3-23, or members of the terpene series, or Cellosolve, or butyl ethers, which serve similarily to octyl alcohol. Therefore, it is understood also,

that several synthetic products or alcohols can be utilized or substituted. Also, it is possible to obtain good flotation results without using octyl alcohol or substitutes according to I the class of :barite and the ingredients associated therewith.

The process consists of a series of steps.- The first step consists of introducing the hereinabove mentioned reagent into a flotation bath.- and comprises subjecting the pulp of the ore to be separated to agitation and aeration in order to form a film on the surface of said barite so that it is activated and collected in a flotation froth; The introduction 'of tannic, citric or tribasic acid is for the purpose of depressing undesirable minerals, such as heavy. iron oxides, siliceous minerals, limestone or calcareous minerals, alumina, manganese, and titanium oxides and impurities included therein, and of causing a' desirable separation of the above minerals. Colloidal iron and aluminahydroxides are not depressed as easily as heavy iron oxides and are dealt within the second step of the process together with' suspended minerals-such as colloidal silica, lime, titanium and manganese oxides.

In its natural state barite is often found in-. timately associated withheavy iron and alumina oxides as well as with colloidal iron and alumina oxides the'latter being strongly adsorbed there- ,to forming an adsorptive film on said minoral and very easily floated with it. Therefore,

in the first step of the process, heavy oxides and undesirable minerals are depressed and separated from barite; at the same time said barite is activated and collected in aflotation froth. In the second step of the process. the reverse operation .is undertaken, that is, the barite is depressed and the colloidal and suspended minerals are activatedand collected in a fiotationfroth. This operation is accomplished by removing or modifying the film formed on said barite by any reagent or chemical which lowers the pH value of the flotation bath, such as tannic, citric, sulphuric acid.

sodium sulphate. If octyl alcohol, heptonals, or

diethylene-glycol-mono-ethyl-ether or aliphatic and aromatic alcohols of the general formulas I RUE-20H and Calla-+101! respectively, chosen from the group having'low. solubility and marked surface tension,'for example, hexanols, heptanols,

octanols, nonanols, decanols and dodecanols are introduced into'the flotation bath, colloidal iron and alumina hydroxides, suspensoids, or suspended minerals are activated and collected in a flotation froth, separating said products from de- Dressed barite.

The process is illustrated further as follows: Grinding and thickening of the millpulp according to regular mill practice. The pulp is passed to a fiotationmachine from a conditioner wherein conditioner reagents are added. The flotation reagent is added to the flotation machine activating barite minerals which are collected as rougher bai'ite concentrates in a flotation froth, while the siliceous minerals. limestones, heavy iron and alumina oxides and impurities contained therein, are depressed. .Ihis is'the first separation of undesirable minerals fromsaid barite. 'Ihetailings from the first rougher machine go to a second flotation machine and so on. while the barite concentrate is returned to. each preceding machine.

The first rougher concentrate. is passed to a cleaner flotation machine in which the first step of the process is involved and the liere'inabove mentioned reagent is a ain added in small quantities'until a final product of barite concentrate is obtained.

The cleaner concentrate from step No. 1 is passed to a second conditioner. to remove the film on the surface of said b'arite as described. The chemicals used are sodium sulphate. sulphuric acid, or trib'asic acids, or tannic acids or citric The conditioned pulp from step No. 1 is d separate the colloids and suspensoids contained 10. therein.

In step No. 1 barite is activated-and collected in a flotation froth while heavy iron and a1 oxides limestones, siliceous minerals and impurities are depressed. The hereinabove reagent is is the collector and frother and forms the film on said barit'e.

In step No. 2 the barite is depressed while colloidal iron and alumina hydroxides and suspended minerals are activated and collected in 20 a flotation froth.

The combination of these two steps remove undesirable minerals from said barite during a repeated cycle until a high grade barite concen= trate is obtained.

as The Table No. 1 indicates that a'barit concentrate was produced assaying as follows: 130.804, 96.20%; FezOa, 0.34%; 810:, 1.40%; A1203, 1.46% from an original ore assaying as follows: Ba804, 77.30%; F6203, 2.66%; 8102,

' 8.73%; and A1203, 4.06%. The colloids and suspensoids associated with this ore interfered considerably with the complete separation of said minerals. Step No. 1 produced a. barite concentrate which assayed B8804, 92.0%; F8203, 1.70%

" S102, 3.5% and AhOs,,2.5%. .As this concentrate does not give a grade whereby the specific gravity is sumcient for commercial use it was necessary to remove colloids and suspensoids as per step ho. 2, which raised the grade of barite concentrate to the assay content as indicated in the Table No. l.- 4 V The pH value of the flotation bath in step No. 2 varied'between 3.55 to 8.2. The-film formed a on the surface of the mineral in step .No. 1 was removed by the procedure in the process known as stepNo. 2. Barite is activated in step No. l but depressed in No. 2. Heavy iron and alumina oxides siliceous minerals, titanium, manganese,

l0. limestone and impurities are depressed in step No. 1, while colloids, suspensoids and suspended minerals are activated in step No. 2. Therefore. the novelty of the process consists of introducing a reagent which has specific properties .or qualities for flotation purposes by selectively separating barite from associated minerals which could not be accomplished similarly by other flotation reagents. Said reagent acts by forming a him on barite to activate it and make it water repellent and in this manner separating said mineral from heavy iron and alumina oxides and siliceous minerals associated therewith. This fllm is removed by subsequent operation designated as step No. 2 for the specific purposes of separating colloids and suspensoids from the bar- 'ite concentrate from step No.1, and whereby the heavy oxides and undesirable minerals associated therewith were'previously removed.

70 Both steps contribute to the continuous separation of barlte from undesirable associated minerals such as heavy iron and alumina oxides, siliceous minerals, limestone, alkalie earths, manganesc, titanium oxides and impurities, by re- 1| pcatingthecycloofstepsrlo. 1andNo.2asmany times as itisynecessary to obtain a high-grade bl'rlte concentrate free from iron and alumina colloids and suspensoids.

The process is illustrated. further and described as follows and whereby grinding, classification and thickening of pulp is undertaken according to regular milling practices for baryta ores.

separation of iron, alumina and silica "colloids" from heavy baryta concentrates contained therein; The critical point at which iron and alumina colloids are activated and collected in a flotation The thickened pulp from the thickener is the feed for the first conditioner where depressors are and collected in a flotation froth while the heavy oxides of iron, titanium, manganese, free silica and lime are-depressed as tailings. The rougher I barytaconcentrates from cell 3 'goes to flotation. cleaner cells of twov or more or thereabout and fed to cell 2; the concentrates from cell 2 goes to cell i; the cleaner concentrates from cell i goes to second conditioner which step is designated as the'ilrst step of the process. sulphuric acid is introduced into the 2nd conditioner to lower the pH value of the bath sufilciently to remove chemical or adsorbed films formed on the surfaces of the mineral baryta which'were acquired in step No. 1 or to make said minerals water-avid" or for "wetting purposes;

also, to break up the flotation froth and prepare the baryta concentrates for depressing purposes, which is known as the beginning of the second step of the process.

'I'herougher concentrate from cell 6 goes to cell from cell 5 to cell 4; and from cell 4 to cell s. I

in the second step of the process baryta concentrates go from the 2nd conditioner to flotation.

cells of four more or less or to cell i; the said baryta concentrates being depressed goes to cell s from cell 1; from cell 8 to cell a; and from cell 9 to cell it. High grade baryta concentrate from cell it goes to dryer and to storage.

"Colloid products, which consist of true colloids, suspensoids and lighter specific gravity minerals with impurities contained therein are activoted and go from flotation cell it to cell 9; from celliltocellt.

The final "colloid products if low grade are returned to sell 3 from cell s and again subjected to the first and second steps of the process. If the final "colloid products are high grade they go directly to the dryer and to storage.

Flotation-cell I is in closed circuit with the second conditioner in order to break up the flotation froth from the first step as well as to loosen or remove the chemical or adsorbed films formed on the baryta concentrate therein.

Octanols or hexanols or heptanols or diethylene-glycol-mono-ethyl-ether or aromatic and allphatic alcohols of the general formulas RCHzOH' and CaHQn-HOH respectively chosen from the group having low solu'bilityand marked surface tension property or members of the terpene series are introduced into cell 8 as'activators, frothers and collectors of colloidsor suspensoids or lighter specific gravity minerals or products, such as, colloidal iron and alumina. silica and impurities. The pH value of the flotation bath is kept near to the isoelectric point or thereabout, in

order-that conditions willbe favorable for the Acid, for example,

froth is for a pH value. of the flotation bath between 2 to 7.5 or thereabouts; and the critical point at which colloidal baryta is activated and collected is for a pH value of said bath between 6.5 to 8.2 or thereabout. Therefore, a separation of iron and alumina colloids from baryta colloids and concentrates is possible by control of the pH valueof the flotation bath and by collecting each mineral in a flotation froth at its critical point of activation and separation.

If true iron and alumina colloids are adsorbed to baryta colloids and the adsorbed films are not table.

completely removedor only partly removed or loosened then both minerals may be activated and collected in a flotation froth. If this product is low grade then it is returned to cell 3 from cell 8' repeating the cycle of steps No. l and No. 2 of the process for this returned produuct. Ifthe product is high grade it joins the flnal baryta concentrate for drying, which is designated for storage. v

The tails from cell 3 go to cell a; from cell t to cell 5; from cell t to cell 6; from cell 6 to pilot The table concentrates and middlings go to cell 3 or back to the grinding department if too coarse for flotation purposes, and the final tails so to waste.-

The final baryta concentrate after it has been filtered is dried in the usual manner at temperatures of 500 F. or thereabout.

The novelty of the process is illustrated by the separation of heavy oxides of iron and alumina, lime and silica and colloids of iron, alumina and silica with impurities, from heavy as well as colloidal baryta concentrates which have been very dimcult tasks to perform economically heretofore by other known flotation methods. This separation is due to the differences in flotation properties of iron and alumina colloids from baryta colloids and concentrates at a critical point of activation and separation of said minerals and colloids for a, definite pH value of the flotation bath.

- sulphate and octyl alcohol in addition to what has already been described is, that said combination as a reagent does not lose its frothing nor collecting qualities ,nor properties while going through the two steps of the process, if the pH value of the flotation bath is kept near to the critical point for separation and activation of the hereinabove mentioned minerals and colloids. For this reason said reagent can be used over again several times in transferring residual amounts of same from cell 8 to cell 8 without deterioration. The novelty of the process consists of step No. 1 whereby a chemical film is formed on the baryta minerals due to the flotation reagent.

It is activated and collected in a flotation froth,

. while heavy oxides of iron, manganese, titanium,

droxides adsorbed to negative colloidal baryta or silica are removed or loosened. This latter step causes baryta concentrates to be depressed while. iron and alumina colloids, suspensoids, and lighter specific gravity minerals and impuri es are activated and automatically separa from baryta minerals by collecting said "colloids" in a flotation froth as hereinabove described.

. Both steps contribute to the efflcient separation of baryta minerals and colloids from the heavy and lighter oxides and colloids iron and alumina, silica, lime and the various metallic or min- Iii By reierence to Table IV it is evident that the removal of "colloids of iron and alumina helps to improve barite concentrate as -a more eiiicient weighting material for mud-laden-fiuidsin rotary drilling Ior oil and gas wells. The Table V shows 'that the water-loss" has improved 20.26% and the initial gel (viscosity) has improved 50% over the same original weighting material before the colloids were removed. s

The tests show that the original high grade barite concentrate containing colloids of iron and alumina with suspensoids is considerably improved by removing said colloids and suspensoids by step No. 1 and step No. 2 of the process.

The tests show that by the lower filter rate, the weighting material is improved by removing the colloids of iron and alumina and suspids. It shows a lower water-loss" and higher mud-yield which in turn means better suspending power, superior gel-strength, viscosity and wall-building properties.

I Taste No. 1

Step No. 1 and step No. 2 of process combined Assn rcent Distribution ercent Product weight y'pe p percent B3804 F6303 810: A120: B5804 F8202 S100 A1001 c010. head 100.00 11.30 0.00 s. 13 4.00 100.00 100.00 100.00 100.00 4000 .20 0.34 1.40 1.40 01.20 1.01 1.30 10.01. 30.20 01.00 0.20 0.10 3. 00 41.53 25.10 30.01 00.00 14.10 0.40 40.00 33.10 12.00 1.22 13.23 00.01 00.00

Step N0. 1

, Reagent in pounds per ton oi ore Reagent I First eon-- First Second First Second T t ditioner rougher rougher cleaner cleaner 0 gauge] fii t di th le l eol 'au 0-80 -68 Bi" 6 Y B- y -un1no- M mumfllp m (20%) f 0.10 0.10 0.08 0.00 0. 00011100.) v V Najslod 0. 20 0. 10 0. 20 0. Quebracho 0. 10 0. 10 0. 05 0. 01s 0. 00 0. 30

pH value 4.0 to 7.5.

Having described the process it is evident that w Step No. 2 many variations of the above are possible, such as reversing steps, No. 1 and No. 2 or by r peating Second the cycles several times for activating and de- 33 elem? pressing baryta concentrates and I coiioi whereby a very high grade baryta concentrate can Oausticsoda 0.10 0.10 be produced from a very low grade baryta ore in 2 011 1 10 3111 11 00. 0.10 0.10 its natural state. P on 1111001101 0.00 0.10 0.04 Also, it may not be desirable to remove iron and Y alumina colloids or the core may not contain HvflmM-m these colloids in which case step No. 2 serves as a recleaner for the pH value of theflotation bath is kept near to its isoelectric point or thereabout.

barlte, colloids and suspensoids.

include heavy harite concentrates and Mldds. are returned to rougher machine tceell 3 in description repeating step i and step 2 oi the process until h s grade.

OTI.?'BQI'1Q concentrates Tsar: No. 2

Step No. 1 and step No. 2 combined my percent Distribution percent P100001 {mg- I B880 1 0,0 0101 A1101 s sol m0. 010, A101 3.01- 10.01 3.10 100.00 100.00 100.00 10000 0.32. 2.00 1.00 1431s 44s 0111 1401 0.10 2.00-- 1.00 11.11 2.01 2.20 0.00 12.10 00.00 10.10 2.40 3320 3040 4114s.

aao 02.40 11.0 0.40 00.04 04.11 41.02

aerate: Y 5

Step No. 1 Tun: No. 5

Showing improved weighting material (BaSOa) T ff gf f i ag g2 for mud-laden fluids by removal of colloids and 1e p on suspensotdsbysteplvo. land No. 201theproc- 5 Step NO. 2 ess from barite concentrate v I Table IV econd moo Table IV Reagents Table I coll. mldds.,

s I I 0 gg g we g-gg r Alignagt ggd elighg tigalcolggs br't'fi zgia tn'egmua' $53 3? F 9 en respec ve y c osen from the group hairingl ow solubility and marked ga f a 2 g 2 g g3; Pmpmy Mud weight.-lbs./cu. it 121. a 122. s 121. s

data: isco ity cpe m H value of flotation bath 2.0 to 4.0. f ifi 3 4 6 OIL-The concentrates and barite colloids are combined into 2 the duel h h grade roducts. The midds. and tails are discarded. 30' wr'water 1053 3 3&0 The table a owe the eavy oxides of Fe,0;Al,O; and Bio; and the N ore-2.6% by wellght solids in mud. Column No. i had a colloids of iron and alumina ydroxides are removed. 1 tendency to settle. Co unms No. 2 and No. 3 were stable.

' TABLE No. 3 v

Steps No. 1 and No. 2 combined I l Assay, percent Distribution, percent Weight Product percent B6804 Si0| F0305 A150, BBSOe S10: FegO; AllQe 100.00 62. 72 32. 58 I 63 8.72 100. 00 100.00 100.) 100.00 17.00 91.00 4.80 0.87 2.03 29.34 2.53 4.08 3.90 19.28 94.00 3.30 0.72 1.68 so 39 1.95 3.83 3.71 26. 48 61.20 30.00 4.92 11.43 24. 75 23.46 81.80 38.55 21. 19. 50. 7. 80 18. 30 7. 97 33. 61 46.13 45. 02 16. 79 11.20 76. 20 3. 06 7. 14 3. 56 '38. 56 14. 16 13. 76

Step No. 1 The table showsen improvement of barite concentrate as a constituent of mud-laden fluids by removing the colloids of iron and alumina d silica from a barite concentrate, by step 1 and Reagents in pounds per ton of ore same as per Table No. 1. pH value 6.5 to 8.2.

Step 2 I step,2 of the process.

semi The Serial Number 517,469 relates to the fiota-' Remus cond. tion reagent employed in the described process 40 for producing high grade loarite concentrate.

Sulphuric o. 40 I claim:

gigilfifffYffkff'ffffwfi ff ji A fmth P e ma H value mm m I ing and aerating a pulp of barite ore associated own-Table shows berite cone. and berite colloids produced with uneconomic minerals including hematite,

from a low rade berite ore. The colloid midds. are returned to cir- 4 5 cuit at 0811 3 for step No. lend step N o. 2 of the recess until high limomte'msgnetite'mmgwesen fang-magnesium, grade cone. is obtained. The mm midds. and s are discarded. calcitic and silicate minera1s,- colloidal and sus- Tesnn No. 4:

Step No. 1 and step No. 2 combined Assay, percent 1 Distribution, percent Weight Product percent B8504 Bio: A1108 m0. B8806 Bios A: FSaOa pH value 4.0 to 7.5, etep No. 1. pH value 6.5 to 8.2, step No. 2.

Step No. 1 pensoidal gangue minerals of Fe, Si and A1, in the f presence of a reagent consisting of talloel, ieuric- Reagent Reagent in pounds per ton 0 re acid -ester-diethyleue-elycol-comm-sulphate same as per Table and an alcohol chosen from the group consisting Step 3 c5 of hexanois, heptanois and cctanols, in the prese s d once or a conditioner chosen from the group con- Sulphuric sold 35 53 sisting of silicates oi code, floating the barite, colioidal and suspensoidel ganeue minerals at a pH value above 6.5 as a flotation concentrate, thereby Sulphuric acid 0. i0 g g fl g-z lv t y t 8 f3 .70 I depressing the uneconomic minerals. then adding y t0 the froth concentrate an acidic substance N OTE.-Th6 table shows the remove! of colloids and suspensoids of chosen from the group c Sting o u phuric acid AlaOr, F0 0; from a very high grade harite concentrate which was 7 product is obtained.

used esbrlm ilmp rioged vfieightifigdmaterielonging-1213651421308testM to lower the pH value to below 6.5' thereebout,

83 No 1 33 3 g g ggt gg g 3 g g fgj amltatine? and aerating said froth concentrate in W the presence or an alcohol chosen Item the group consisting oihexanols, heptanols, and octanols to produce .a iroth containing colloidal and suspensoidal gangue minerals, and thereby depress-' I asvasss 4. A froth flotation process, comprising, agitat= ing and aerating a pulp or barite ore associated with iron and aluminum oxides, impurities in= eluding heavy oxides of Fe, ferro-magnesi, calcitic silicates, manganese, titanium minerals in the presence of a reagent consisting of talioei,

- lauric-acid-ester-di ethylene-glycol-ammoniuinand Si, and uneconomic minerals including heavy oxides of iron, term-magnesium, titanium, manganese and silicate minerals, which comprises, subjecting a pulp of the ore to be concentrated to agitation and aeration, in thepresence of talloel,lauric-acid-ester-di-ethylene-glycol-ammonium sulphate and, an alcohol chosen from the group consistingior hexanols, heptanols, and octanols, in the presence of .a conditioner selected from the group consisting of silicates of soda, floating the barite, colloids and suspensoids of Fe, Al, and Si at a pH value above 6.5, thereby depressing uneconomic minerals, then adding to the iroth concentrate an acidic substance chosen from the group consisting of sulphuric 'acid, which lower the pH value to below 6.5 thereabout, agitating and aerating the flotation froth concentratein thepresence of an alcohol chosen from the group consisting of hexanols, heptanols and octanols, to produce a i'roth containing colloidal and suspensoidal minerals of Fe, A1 and Si, and

thereby depressing: barite, separating said minerals from each other, as described. a

3. A flotation process for concentrating barite ore associated with colloidal and suspensoidal V gangue minerals of iron, alumina, silica, ierromagnesium, calcitic, manganese, titanium and silicate minerals, in the presence or iauric-acidester di ethylene-glycol ammonium-sulphate, talloel. and an alcohol chosen from the group a5 thereabout, agitating and aerating said froth concentrate in the presence or an alcohol chosen from the group consisting oi hexanols, heptanols and octanols to produce a flotation froth containing colloids and suspensoids of Fe, Al, and Al, and

thereby depressing the economic mineral barite,

separating said minerals from each other.

. consisting of hexancls, heptanols, and octanols,

sulphate and an alcohol chosen from the group consisting of hexanols, heptanois and octanols, in the presence of a conditioner chosen from the group consisting of sodium silicate, floating the barite and colloidal and suspensoidal gangue minerals at a pH value between 6.5 and 8.2 thereabout. as a flotation concentrate, thereby depressing heavy oxides of iron and alumina, silicates, calcite's, manganese and titanium minerals, alkaliearth-minerals and ferro-magnesium rais, then adding an acidic substance chosen from the group consisting of sulphuricacid, citric, tannic and phosphoric acid to the froth concentrate until the hydrogen ion concentration is below 6.5 thereabout, agitating and aerating the froth concentratein the presence of an alcohol chosen from the group consisting of hexanols, heptanols and octanols, to produce a froth containing the colloidal and suspensoidal gangue minerals and thereby depressing the economic mineral barite, separating said minerals from each other, as described.

5. A froth flotation process, comprising, agitating and aerating a pulp or barite ore associated with iron and aluminum oxides and colloidal gangue minerals and impurities including heavy oxides of Fe, term-magnesium, calcitic, silicate, manganese and titanium minerals, in the presence of a reagent consisting of talloel lauric=acidester (ii-ethylene glycol ammonium-sulphate and an alcohol chosen from the group consisting of alcohols of the general formula CnHQn-HOZ'i, with n==6 to 8 inclusive, in the presence of con-= ditioners selected from the group consisting of citric, tannic phosphoric and their allied alkalimetal salts, floating the barite, colloidal and sus=- pensoidalgangue minerals at a pH value above 6.5, thereby depressing minerals of iron, siicate calcites, alkali-earth-metals, titanium and ma ganese minerals, form-magnesium and alumihum-silicate minerals and impurities associated .ing oiv hexanols, heptanols and octanols and thereby separating depressed barite from floated colloidal and suspensoidal minerals, as described.

E. H. HQAG. 

